A boy said his friends "I____________{not skate} on a real lake before .It is wonderful!Look!I ______{fly}!"Suddenly the
问题描述：
A boy said his friends "I____________{not skate} on a real lake before .It is wonderful!Look!I ______{fly}!"Suddenly the ice broke .One of the boys_____[fall}into the water.The children shouted,"Help!Help!"They did not know what they ___{do}.
答
第一空 will not skate
第二空 am flying
第三空 fell
第四空 were doing